When Moses led the Hebrews to Mount Sinai, he explained that God wanted to sign a blood pact or covenant with them. He then climbed the mountain to receive the terms–the 10 commandments. A month passed with no word from the prophet. The Hebrews grew restless and eventually abandoned their God. They demanded that Moses' brother Aaron create a statue of Hathor, the Egyptian goddess of fertility. She was often pictured as a calf.
The key scene in this story is that of Moses pleading to God for the forgiveness of the people. The Psalms picture him as standing in a breach between two rocks–sort of straddling both heaven and earth.

Today's Gospel begins with a stinging criticism of Jesus: he eats with sinners! Tax collectors were little more legalized thieves in 1st century Palestine. Worse yet, they were traitors who collaborated with the occupying government. "Good people" didn't associate with them, much less break bread with the unsavory lot. They were literally excommunicated from "polite" society.
Jesus counters this self-righteousness with three parables. They illustrate the joy brought by conversion.